The present invention relates to magnification viewers worn by surgeons and dentists. In particular, the invention relates to an assembly for optical views or loupes which allow a user to adjust an objective lens at a predetermined distance from an eyepiece lens to vary the focal point.
Magnification viewers, including, but not limited to, pairs of magnification loupes, are worn by dentists and surgeons for extended periods of time during clinical procedures. These viewers are worn to provide clarity of view while avoiding a hunched-over position that can result over time in debilitating neck and back strain, which can also have an adverse effect on the success of the operation. The viewers permit the clinician to operate at a greater working distance from the patient. Higher magnification viewers also reduce the clinician""s exposure to aerosols. Because clinicians use magnification viewers during surgery and other procedure requiring manual precision, it is important that the viewers be light-weight, comfortable and have good clarity and wide field of vision while providing high magnification and good depth of field.
Surgical telescopes may be attached to a spectacle frame in one of two manners: outside-the-carrier or prescription lens (xe2x80x9coutside-the-lensxe2x80x9d), on an adjustment mechanism that provides for adjustment of the interpupillary distance and convergent angle variability, or through-the-lens, permanently cemented and fixed in place. Magnification viewers used by surgeons and dentists typically have a predetermined magnification. Neither the working distance nor the magnification may be changed without a tedious process of replacing either individual lens elements or the entire optical loupes themselves. Accordingly, there is a need for a simple method for changing the magnification of viewers being worn by a surgeon or dentist, as well as for altering the working distance of viewers having a particular magnification.
In accordance with one embodiment of the invention, a housing for a magnification loupe is provided having an eyepiece portion for an eyepiece lens and a nose portion for an objective lens. The body portion for the eyepiece lens includes outer circumferential threads over which the objective nose portion fits. The objective nose portion includes a pair of apertures for receiving a pin. The apertures are configured such that the pin forms a chord across the body of the nose portion and co-acts with the threads of the eyepiece body forming an axial mechanical stop to prevent the nose portion from being removed during adjustment.
Magnification loupes, according to the present invention, include a nose housing for an objective lens and a body housing for an eyepiece lens. The system is configured such that the magnification of the magnification loupe may be changed simply by removing the nose housing and replacing it with another. The working distance for a particular magnification level may be adjusted by threading or unthreading the nose housing.